Good idea !
but as to be safe ;"Just remember that chambers have actually blown up (not in the US) because of static electricity, or materials brought in that should not have been.
Something New (and Dangerous) to Watch For!!!
http://www.hbot.com/somethingnew.htm
One way can of using is with a mask and hood systems use intake and exhaust hoses for the oxygen to make a sealed breathing circuit that exhausts outside the chamber. Sealed circuits prevent oxygen build-up into the chamber atmosphere.
check this for infos:
http://www.oxytank.com/ http://www.hbot.com/
The hyperbar (1 ATM.pressure )setup can be very expensive.
How much do you think building such tank will cost ?
Antonio